<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <style>
        
    </style>
</head>
<body>
    
</body>
<script>

    var a = 10;

    // a = a + 1;

    // a += 1;

    // a -= 2;

    a *= 2;

    // a /= 3;

    // a %= 3;

    console.log(a);
    
</script>
</html>